The present invention relates to an image forming apparatus and more particularly to an apparatus for storing sheets carrying images thereon and output from an image forming apparatus in a plurality of bins or bin trays thereof.
A sheet storing apparatus of the type described is extensively used with various kinds of image forming apparatuses including simple printers and copiers. The sheet storing apparatus including a plurality of bins is used in combination with a single tray for simply stacking sheets driven out of the image forming apparatus. Sheets sequentially discharged form the image forming apparatus are conveyed to the storing apparatus in a sort mode or to the tray in a mode other than the sort mode.
In the sheet storing apparatus, the bins are stacked one above the other. A sheet driven out of the image forming apparatus and conveyed by sheet feeding means is steered, or deflected, away from a transport path at an insertion position facing the inlet of a preselected bin. As a result, the sheet is received in the bin via the inlet. To cause the inlet of any desired bin and the insertion position to face each other, it is a common practice to move one of them relative to the other. With this scheme, it is possible to sequentially distribute sheets continuously conveyed by the sheet feeding device to the stack of bins.
For example, Japanese Patent Laid-Open Publication No. 49-99038 (corresponding to U.S. Pat. No. 3,788,640) teaches a sorting apparatus in which a stack of bins are moved up and down by cylindrical cams relative to a fixed insertion position where a sheet is steered away from a transport path. The bins are sequentially brought to the insertion position with their inlets sequentially broadened. A sheet is inserted into the broadened inlet of the bin located at the insertion position.
Japanese Patent Publication No. 3-6104 (corresponding to U.S. Pat. No. 4,478,406) discloses a sorting device in which an insertion position for sterring a sheet away from a transport position is movable. Cams facing the insertion position are rotated and moved upward or downward relative to a stack of bins, moving one bin facing the cams form one adjoining bin toward another adjoining bin. At this instant, the inlet of the one bin or that of one of the adjoining bins is broadened and caused to face the insertion position for thereby receiving a sheet. In this manner, sheets are sequentially inserted into the consecutive bins. This apparatus moving the cams up and down relative to the stack of bins reduces the moving range of the bins and therefore the overall height of the apparatus.
Japanese Patent Publication No. 56-7952 (corresponding to U.S. Pat. No. 3,765,670) proposes a sorting machine includes a stationary bin unit having a stack of bins, and a deflector assembly movable up and down relative to the bins on a vertical transport path. The deflector assembly deflects a sheet conveyed downward along a transport path at a sequentially varying insertion position, thereby inserting the sheet into one bin. Although this machine needs a relatively great distance between nearby bins and therefore renders the bin unit bulky, it does not need, e.g., cams for broadening the inlets of the bins.
The sorting apparatus taught in the above Laid-Open Publication No. 49-99038 has a problem that it includes too many sliding portions and movable portions to implement high-speed processing and sufficient reliability. Specifically, in the sorting apparatus, three cylindrical cams positioned vertically are rotated at the same time in order to move the stack of bins engaging therewith in the up-and-down direction, while the inlets of the bins are sequentially brought to the insertion position. The sorting machine taught in Publication No. 56-7952 has a drawback that the bin unit is bulky and occupies a broad space.
The sorting device disclosed in Publication No. 3-6104 successfully reduces the moving range of the stack of bins and therefore overall size of the device. However, the sorting device lacks in reliability as to the insertion of a sheet into the inlet of the bin based on the interlocked movement of the deflector and cams and as to high-speed operation.
Technologies relating to the present invention are also disclosed in, e.g. Japanese Patent Laid-Open Publication Nos. 7-309520 and 7-41238, Japanese Patent Publication Nos. 57-27752 (corresponding to U.S. Pat. No. 3,944,217), 60-10309 (U.S. Pat. No. 4,203,587) and 63-15223 (U.S. Pat. No. 4,352,490), Japanese Patent Publication No. 2-23464, and Japanese Patent Laid-Open Publication No. 60-137769.